1. Field of the Invention
The present invention relates to fluid tubing, and, more particularly, to a method of manufacturing coated fluid tubing such as fuel or brake tubing for use in a motor vehicle.
2. Description of the Related Art
Fluid tubing may be used in known manner to carry pressurized fluid for a specific application. For example, fluid tubing may be used as fuel or brake tubing for use in motor vehicles. Fuel and brake tubing is typically carried on the under carriage of a motor vehicle, and is thus exposed to water and chemicals such as salt, calcium chloride, etc. Accordingly, it is desirable to coat fuel and brake tubing with a metal coating and/or plastic coating to provide improved corrosion resistance and extended life.
Although a plastic coating on the outside of fuel and brake tubing substantially increases the life of the tubing, the plastic also provides manufacturing difficulties which must be overcome. For example, the end of the fuel or brake tubing is connected to another mechanical component in the fuel or brake system which usually requires that the end of the fuel or brake tubing be flared, swedged, beaded, or otherwise formed. The plastic coating must be completely removed from the metal tube prior to the flaring, swedging, beading or other operation. If the plastic is not removed, the metal tube may be damaged and/or the tubing may not properly seal with the connected mechanical component.
It is known to use a laser to remove a plastic coating from the outside of fuel or brake tubing. The power level of the laser is adjusted such that most of the plastic coating is burned off of the fluid tubing while the underlying metal tube remains substantially intact. A problem with using a laser to remove the plastic coating from the metal tube is that the plastic is burned off of the metal tube and leaves a residue layer on the outside of the metal tube. The residue layer may interfere with the sealing of the fluid tubing, and is aesthetically unappealing. Moreover, using a laser to burn the plastic from the outside of a metal tube takes a relatively long period of time which may not be acceptable for mass production items. For example, using a laser to burn the plastic coating from the end of fuel or brake tubing for a distance of slightly less than one inch may require approximately 30 seconds. This is a relatively long period of time for mass production items such as fuel or brake tubing which may not be acceptable.
What is needed in the art is a method of manufacturing fuel or brake tubing so that a predetermined length of the plastic coating can be quickly, easily and cleanly removed from an end of the tubing.